Fluid filtering method

ABSTRACT

A method of filtering water utilizing separate beds of non-soluble ceramic-type calcium sulfite beads, made from a ceramic binder and calcium sulfite, and a copper-zinc media, with the ceramic-type calcium sulfite beads and the copper-zinc media being in substantially equal volumetric portions.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation-In-Part of application Ser. No.08/703,943, filed Aug. 28, 1996, which was a Continuation-In-Part ofapplication Ser. No. 08/581,044, filed on Dec. 29, 1995, both nowabandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to treatment of fluids and moreparticularly to a method for increasing the efficiency of filter mediain the removal of unwanted contaminants, such as chlorine, from hotwater during showering.

2. Description of Related Art

Starting after the U.S. Civil War, the recognition and linking ofmacroscopic and microscopic pathogens to the aesthetic and healthqualities of water resulted in the search for effective waterdisinfection and treatment procedures. Soon thereafter, chlorine wasidentified as a disinfecting agent. Towards the end of the 19th century,there were several recorded instances of the use of chlorine compoundsfor the disinfection of water and, with increasing experience, theeffectiveness of chlorine treatment of water became more widelyrecognized and appreciated. The introduction of water chlorination, as acontinuous process, occurred soon after the turn of the century.Currently, approximately 80% of all potable water systems in the U.S.contain chlorine as a disinfectant.

Different devices and methods for dechlorination of water have been usedboth at the point-of-entry ("POE") into a commercial, industrial orresidential building, and the point-of-use ("POU") at the faucet, showerhead or tap.

POE systems typically are in the form of an aerator, or a large organicor inorganic filtering media bed. Although applicable in some instances,these systems have potential problems, and have fallen under closescrutiny, due to the possibility of pathogenic reintroduction back intothe water system, after the point of dechlorination. Because of thispossibility, and the recent advancement in water treatment technology,POU water treatment systems have become widely accepted and are nowprimarily used in residential, and to a large degree, in commercial andindustrial applications.

Both organic and inorganic filtering media are known for use indechlorination. Carbon (organic) filtering media are used either alone,or in conjunction with other systems, such as reverse osmosis ordistillation, or may be used with inorganic filtering media, such ascation/anion resins.

Currently, shower filters are known which use various types of materialsto filter out impurities in water. However, the performance of suchshower filters is restricted by the water's high flow rate and the hightemperatures of the water. Traditional filtration methods havehistorically relied on carbon as the filtration media, using the processof adsorption to remove contaminants such as chlorine. The mechanics ofadsorption involve a finite number of molecular attachment sites locatedin each granule of activated carbon. Often compared to a sponge, carbon"pulls" contaminants out of the water by an electrochemical chargelocated at each site. Used for removing the free and combined (or total)chlorine from drinking water at typically lower flow rates and at roomtemperature (25 degrees C.), carbon is quite effective.

However, carbon's shower water filtration efficiency is limited by thehigher flow rate and high temperatures of shower water. In fact, carbonhas a tendency to release previously adsorbed contaminants back into thewater stream when temperatures approach the contaminants' boiling orvaporization point. Chlorine has a relatively low vaporization point.The releasing (off-loading) of chlorine begins when the watertemperature is at about 90 degrees.

A partial solution to filtration of shower water at high temperaturesand flow rates came with the use of granular copper and zinc. This mediautilizes different filtration mechanics. Instead of pulling contaminantsout of the water through the process of adsorption, as the carbon does,the copper and zinc (being very dissimilar metals) create an increasedelectro-negative potential in the water. Free chlorine is converted toan FDA "food grade" safe substance, zinc-chloride. This process israther selective. Even though the free chlorine is converted, the manymolecular combinations of chlorine (combined chlorine) are not affected,and remain in the water.

It is the free (uncombined) chlorine that is introduced into the waterfor disinfection purposes. It easily passes through the cell wall of thepathogen and attaches to the fatty acids in the cell creating complexchloro-compound. Once this occurs, cell functions cease and pathogendies. The same processes occur when the human body is exposed tochlorine. Symptoms of chlorine exposure ranges from dry, itchy-flakingskin, scalp and hair to epidermal rash, and even to colon, liver andbladder cancer. Effective as copper-zinc filtration is, it also has itslimits. In the case of chlorine, it is chlorine-free specific. That isto say that it only affects the free chlorine and not the combinedchlorine. Copper-zinc has two main problems: 1) it cannot convert themultitude of combined chlorines; 2) it requires a temperatureenvironment of over 90 degrees (F.) to effectively convert the freechlorine.

Another type of prior art filter media is disclosed in U.S. Pat. Nos.4,642,192 and 5,122,274, which disclose an "electronegative cellpotential type" chlorine filter media. The preferred media to filter outchlorine disclosed in these patents is brass (a mixture of copper andzinc).

Two types of shower filters devices are disclosed in U.S. Pat. Nos.5,152,464 and 5,300,224 to Fredrick A. Farley. The devices disclosed inthese patents are compact filter assemblies containing a filteringmedia, such as copper and zinc, to filter out unwanted chlorine in waterpassing through the filters.

U.S. Pat. No. 2,582,388, discloses another prior art water filter, forinsertion into a waterline, having two parts threaded together to form ashell or housing, with a plurality of screens held in an inlet to and anoutlet from the interior thereof. Layers of activated charcoal,separated by a layer of silica and screens are arranged in the shell tofilter water passing therethrough.

U.S. Pat. No. 3,760,951, incorporates U.S. Pat. No. 2,582,388 therein byreference, and discloses a similar water filter for insertion into awaterline by means of quick-disconnect bayonet fittings that allow thefilter to be easily removed for cleaning or replacement.

U.S. Pat. No. 3,780,869, discloses a water filter, for insertion into awaterline, having a plurality of compartments with multiple filteringelements of sheep's wool therein.

U.S. Pat. No. 3,822,018, discloses a water filter, for insertion into awaterline, having two hemispherical sections joined together by threadedportions. The filter has a plurality of cylindrical filter elementsannularly arranged therein containing natural wool, charcoal, cork andthe like, and includes a valve for directing water through the filterelements or for directing water through the device, unfiltered.

U.S. Pat. No. 4,107,046, discloses a filter cartridge for an internallyby-passable water purifier apparatus. The apparatus includes valve meansfor directing water through the filter cartridge, which containsgranulated carbon mixed with a silver zeolite, and may be sandwichedbetween fibrous sheets of material, such as felt, before it exits theapparatus.

U.S. Pat. No. 4,172,796, discloses a water faucet having a waterpurification or filtering means, made from activated carbon, or carbonwith oligodynamic silver, formed therein.

U.S. Pat. No. 4,504,389, discloses a water faucet having a separatehousing containing a removable cartridge or filter element made fromvarious stages of polyethylene and activated carbon particles therein.

U.S. Pat. No. 5,008,011, discloses a shower dechlorinator fabricated inthe form of a short cylindrical filter housing having two separate endcaps with inlet and outlet means for attachment between the outlet pipefor a shower and a shower head. The filter housing is filled withgranulated or randomly oriented fibrous material in the form of acopper-zinc metal alloy.

While the foregoing prior art devices, filter media and methods provideimproved filtration of water passing through them, they are not adaptedto meet the health and safety standards of today, nor do they meet therequirements, such as in homes, that larger volumes of heated waterhaving increased amounts of unwanted impurities therein be safelyfiltered out during showering. Furthermore, while the above-mentionedprior art provide some limited improvements in the filtering art, thereremains the need in the art for a method that provides the mostefficient filtering out of unwanted materials, such as chlorine, fromhot water during showering, while at the same time meeting the morestringent health and safety regulations of local communities and suchgovernmental agencies as the EPA.

SUMMARY OF THE INVENTION

Accordingly, it is a general object of the present invention to providean improved shower water filtering method. It is a particular object ofthe present invention to provide an improved method for filteringcontaminants from shower water. It is a still more particular object ofthe present invention to provide an improved method for filteringcontaminants from hot water passing through a shower filter at high flowrates. It is yet a more particular object of the present invention toprovide an improved shower water filtering method using non-solublecalcium sulfite. It is a further object of the present invention toprovide a shower filter method that meets the demanding filteringcapacity and temperature requirements of modern water supplies havinghigher concentrations of toxins therein, and at the same time meetingthe more exacting governmental requirements for use with potable water,and the environmental concerns of less waste of materials and energy byimproving the efficiency of the shower water filtering process.

In accordance with one aspect of the present invention, there isprovided a method to treat shower water, and particularly hot water,passing through a bed of non-soluble calcium sulfite. The non-solublecalcium sulfite may be combined with copper-zinc, thus allowing for theimproved treatment of hot shower water, at high flow rates.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is provided to enable any person skilled inthe art to make and use the invention and sets forth the best modescontemplated by the inventor of carrying out his invention. Variousmodifications, however, will remain readily apparent to those skilled inthe art, since the generic principles of the present invention have beendefined herein specifically to provide an explanation of a novel fluidfiltering media and method for use in filtering toxic substances, suchas contaminants, from water.

It has been discovered that calcium sulfite (CaSO₃) when madesubstantially non-soluble, as by being combined with a ceramic binder,as described below, and used alone, or in combination with copper-zinc,produces unexpected and surprising results by eliminating morecontaminates, such as total chlorine from shower water, over a longerperiod of time. In addition to its improved removal capabilities, itwill effectively operate at temperatures as low as 55 degrees. A typicalchemical conversion would be:

    HOCL+CaSO.sub.3 CaSO.sub.4 +HCL

Calcium sulfite, which is naturally occurring or synthetically made, hasbeen used, or suggested for use in filtering water. However, as pointedout in column 1, lines 14-18 of U.S. Pat. No. 3,746,174 and as is knownin the water filtering industry, as water flows through the calciumsulfite, its effectiveness is decreased, and the calcium sulfite must bereplaced in a short period of time. However, after the extensive testingof various materials and combinations of materials unsuccessfully, thepresent invention was found to provide a unique method of extending thelife and usefulness of calcium sulfite when used alone, or incombination with a copper-zinc media, in approximately equal volumes.This inventive combination produced surprising and unexpected results.

Powdered or dehydrated calcium sulfite is highly soluble, and when addedto water having chlorine therein produces calcium chloride, a salt whichis not recommended or desired for drinking, bath or shower water.Therefore, calcium sulfite is primarily used in large commercial orindustrial application, and because of the unacceptably high level ofsalt by-products, is not now used as a point-of-use drinking waterfilter media. Furthermore, because of the higher temperatures and flowrates produced when a typical 5 to 10 minute hot shower is taken,calcium sulfite is not used in, nor is it suitable for use in showerfilters. That is, at the higher temperatures and flow rates in a showerfilter, the calcium sulfite would dissolve even more rapidly, requiringconstant replacement.

Applicant, however, has created "ceramic-type calcium sulfite beads" orparticles by combining powdered calcium sulfite with ceramic binders,such as, but not limited to polyvinyl alcohol (PVA), polyethylene glycol(PEG) and polyacrylics. The ceramic-type calcium sulfite beads of thepresent invention are manufactured by using low temperature, insolubleceramic binders. Unlike other forms of calcium sulfite agglomerates(particles), ceramic-type calcium sulfite is highly insensitive tore-hydration when immersed in water over long periods of time. Since theceramic binder is insoluble, when combined with powdered calciumsulfite, the ceramic-type calcium sulfite agglomerate is insoluble. Theimportance of insolubility becomes evident when considering the highertemperatures, flow rates and volume of water associated with showerfiltration. Particle integrity determines overall filtrationperformance.

Calcium sulfite and ceramic binders (preferably acrylic) can be mixedtogether using a variety of agglomeration (particle forming) processes.Currently, the ceramic-type beads of the present invention are formed ina disk pelletizer. Calcium sulfite is first milled to a fine powder andthen tumbled in the disk pelletizer. Liquid acrylic ceramic binder issprayed onto the powder through a spray bar causing the particles toadhere to each other. As the powder is tumbled, a "snowball effect"begins. The sprayed powder forms larger particles. Once the correct beador particle size has been achieved, the moist particles are ready to bedried (dehydrated).

The drying process creates the ceramic-type beads or particles. Wheninitially applied, the liquid ceramic binder is a copolymer chain.Dehydration transforms (unzips) the two-dimensional copolymer chain intoa three dimensional ceramic polymer matrix. The integrity of the matrixdepends on the extent of dehydration. The presence of a hydratedcopolymer chain link within the partially dehydrated polymer matrix,impedes matrix bonding, significantly reducing the structural integrityof the matrix. The strength of the matrix is referred to as the "greenstrength" of the ceramic-type calcium sulfite beads. The green strengthof the beads increases as they are dehydrated. Dehydration can beachieved by airing at room temperature or placing the beads in a form,or the like in an oven and firing (heating) to 400° C. The firing of thebeads results in the greatest degree of particle dehydration.Dehydration of the ceramic-type calcium sulfite beads, surprisinglyrequires lower temperatures than the 1000° C. normally required byLegonosulfonates commonly used in the ceramic, refractory and brickindustry.

The ceramic-type calcium sulfite beads of the present invention areformed with a hard exterior surface, but are still sufficiently porousthat they may be used in a shower filter. As is well know, showerfilters are subject to a greater flow of water at elevated temperaturesand pressures, than is the case with drinking water coming from a faucetor tap. Furthermore, using these ceramic-type calcium sulfite beads withan equal mixture of a copper-zinc material, such as KDF, substantiallyelevates performance of the combined elements and entirely unexpectedresults are obtained. That is, the ceramic-type calcium sulfite beadsand the copper-zinc material work longer and harder to remove all of thechlorine, not just free chlorine, from the elevated temperature waterpassing through the shower filter.

The hard exterior shell or surface of the ceramic-type calcium sulfitebeads of the present invention allow the calcium sulfite to dissolvemore slowly. Furthermore, as disclosed herein, the specific formulationshave been found to optimize the advantages of the calciumsulfite/copper-zinc combination. Additionally, the present inventionemploys the unique use of and combination of materials herein disclosedin an inventive formulation or method that allows the materials used toact synergistically with each other to perform functions not taught orforeseen heretofore.

Specifically, the combination of the ceramic-type calcium sulfite beadsand copper zinc herein disclosed, particularly in the specified ratio,greatly improves upon the filtering capabilities of known filter mediain a totally unexpected manner. The increased filtering ability of thecopper-zinc media by the addition of non-soluble ceramic-type calciumsulfite beads, is a result which was not foreseen or predicted in anyprior art.

In the present invention, the use of the ceramic-type calcium sulfitebeads in combination with the copper zinc, acts synergistically, notonly to filter out contaminants from water, and particularly hot showerwater, but also to enhance and expedite the shower filtering process,for a longer period of time, thus greatly increasing the effectivenessof the filtering process.

To prove the effectiveness of the present invention, a test bench wasprepared consisting of the following set-Up:

A faucet-hose/multiple shower arm assembly was constructed and attachedto hot and cold water outlets. The hot and cold water converged into asingle hose so that water at temperature of 100° F., was passed througha selected one of the filters at a rate of 3.0 gals/min. A Chem-TekPulsafeeder (model 100/130) injected chlorine into the water atapproximately two parts per million. The chlorinated water then ran to a3-way diverter. Attached to the 3-way diverter was:

#1 diverter--A first shower head and shower filter having only highlysoluble, powdered calcium sulfite therein. After approximately 200gallons of water had passed through the filter, the soluble calciumsulfite had completely dissolved. Furthermore, samples of the productwater taken during this period when the calcium sulfite was dissolvingrevealed an unacceptably high level of calcium chloride--as high as20-25 PPM.

#2 diverter--A shower head and shower filter containing approximately 3cubic inches or 18 ounces of ceramic-type calcium sulfite beads. Duringthe passage of approximately 1,500 gallons of water through the filter,100% of total chlorine was removed. This rate tapered off toapproximately 75% removal of total chlorine at about 2,500 gallons.Calcium chloride levels ran at approximately 5-7 PPM during this time.

#3 diverter--A shower head and shower filter containing approximately50% of a copper-zinc media by volume and 50% ceramic-type calciumsulfite beads by volume. Total removal of 100% of total chlorine wasachieved up to approximately the 2,500 gallons, while a drop off to 75%removal of total chlorine occurred at approximately 4,000 gallons.Calcium chloride levels dropped to 1-2 PPM.

Additionally, the ceramic-type calcium sulfite beads were tested alone.Approximately 3 cubic inches of the ceramic-type calcium sulfite beadswere placed in a cartridge column and retained by a smaller mesh sizescreen placed at each end. The cartridge was inserted into a showerfilter housing and attached to 100° F. water, flowing at 3.0 gallons perminute. The total chlorine content was at 2.0 parts per million. Tracesof total chlorine were detected after only 180 gallons had passedthrough the filter. The testing was stopped and the cartridge removedfrom the housing. At that point, an equal amount by volume (3 cubicinches) of copper-zinc powder was added to the ceramic-type calciumbeads and the test was resumed. Total chlorine was immediatelyeliminated and continued to show "no trace" in the shower water for over2500 gallons, where chlorine started to bleed through. Thereafter, theremoval rate of total chlorine dropped until it reached about 75% atapproximately 4,000 gallons.

CONCLUSIONS

Results show that with a shower filter having ceramic-type calciumsulfite beads alone, improved results are obtained, while a combinationof ceramic-type calcium sulfite beads and copper-zinc in relativelyequal volumetric proportions, produces an unexpected enhancement inperformance. That is, with the combination, a 66% increase in filtrationcapacity is obtained with a 66% reduction of the objectionable saltby-products.

To date, it is not exactly clear as to the entire reaction responsiblefor the ceramic-type calcium sulfite beads alone or in combination withcopper-zinc dramatic performance. However, it appears that thecopper-zinc maintains a priority of reducing the free chlorine, which inturn frees up working capacity of the ceramic-type calcium sulfite beadsfor removing the combined chlorine. On a more subtle level, thecopper-zinc creates an electronegatively charged environment which notonly reduces free chlorine, but increases the potential for otherelectrochemical reactions (in the form of reduction or oxidation) tooccur. By-products produced by the soluble calcium sulfite were in suchhigh concentrations that the brine may have masked any effect that anincreased electronegative potential could have. However, by creating aninsoluble calcium sulfite, in the form of ceramic-type beads, andtherefore, greatly reducing the production of by-products, theadditional electronegative charge associated with the introduction ofthe copper-zinc was "unveiled". In the concentration of 50--50 (% byvolume) the added charge of the copper-zinc helped to drive the reactionthat normally would require a higher concentration of calcium sulfite toovercome the higher energy threshold of the reaction that existednaturally when not exposed to the added e-potential.

That is, it appears that by reducing the solubility of calcium sulfiteby providing it with a hard exterior surface, and introducing theelectronegative charged environment, an unexpectedly low amount ofmaterial is required to obtain the desired results, i.e., removechlorine and, therefore, as a bonus, an absolute minimum ofobjectionable by-products are created. This yields water that is fit forconsumption, as well as improved use for showering.

The ceramic-type calcium sulfite beads have been or can be created bythe process set forth above, or any other known process, in order toform the desired ceramic-type beads, or particulation. The resultingceramic-type beads, or bead-like particles, are typically spherical orconvoluted, but may be made into other shapes. The ceramic-type beads orparticles are then sorted by mesh size and used as desired, or as calledfor. As discussed above, the ceramic-type calcium sulfite beads with theselected binder therein remove total chlorine in a more even andefficient manner, than heretofore was possible.

The ceramic-type calcium sulfite beads, alone or combined withcopper-zinc, may be held within the internal chamber of any commerciallyavailable shower filter element or housing, mixed together or placed inseparated beds. In a preferred embodiment, separate beds havingapproximately the same volume (50--50), are used to more effectivelydecontaminate hot water, passing through the shower filter atsubstantially any flow rate. Furthermore, it allows a much greatercapacity or volume of water to be passed through the shower filter,while at the same time allowing water at elevated temperatures to beefficiently filtered or dechlorinated.

It, therefore, can be seen that the method or process of the presentinvention provides both an increased volume and temperature efficiency,in comparison to known filtering media and methods. Furthermore, aspointed out above, the combined media reacts even more completely withchlorine, to thereby produce a more complete dechlorination of waterpassing therethrough, for a longer period of time, thus producingsavings in the use of energy and materials.

Accordingly, as will be apparent to those skilled in the art, thepresent invention provides considerable advantages in ease andflexibility of filtering chlorine or other unwanted substances fromwater, and particularly, provides a unique method for removing chlorineor other substances from hot water during showering. Specifically, themethod disclosed herein more efficiently and safely removes chlorine andother toxic substances from water, even at elevated temperatures,without any known adverse health risks.

Those skilled in the art will appreciate that various adaptations andmodifications of the just-described preferred embodiments can beconfigured without departing from the scope and spirit of the invention.Therefore, it is to be understood that, within the scope of the appendedclaims, the invention may be practiced other than as specificallydescribed herein.

What I claim is:
 1. A method of filtering water comprising the steps of:combining calcium sulfite with a ceramic binder to form non-soluble ceramic-type calcium sulfite beads; placing said ceramic-type calcium sulfite beads as a bed in a water filter container; and passing the water through the bed in the water filter container to filter the water.
 2. The method of claim 1, including the further step of placing a copper-zinc filter media as a second bed in said water filter container and passing the water through the second bed in the water filter container to filter the water.
 3. The method of claim 2 wherein said ceramic binder is selected from the group consisting of polyvinyl alcohol, polyethylene glycol and polyacrylics.
 4. The method of claim 2 wherein said ceramic-type calcium sulfite beads and said copper-zinc filter media are placed in said water filter container in approximately equal volumetric portions.
 5. The method of claim 4 wherein said ceramic binder is selected from the group consisting of polyvinyl alcohol, polyethylene glycol and polyacrylics.
 6. The method of claim 1 wherein said ceramic binder is selected from the group consisting of polyvinyl alcohol, polyethylene glycol and polyacrylics.
 7. A method of filtering shower comprising the steps of:combining powdered calcium sulfite with a ceramic binder to form non-soluble ceramic-type calcium sulfite particles having a hard, porous shell; placing said non-soluble ceramic-type calcium particles in a shower filter container; and passing shower water though said non-soluble ceramic-type calcium sulfite particles in the shower filter container to filter shower water.
 8. The method of claim 7 wherein said ceramic binder is a ceramic binder selected from the group consisting of polyvinyl alcohol, polyethylene glycol and polyacrylics.
 9. The method of claim 7, including the further step of placing a copper-zinc filter media as a second separate bed in said shower filter container and passing the shower water through the second bed in the shower filter container to filter.
 10. The method of claim 9 wherein said ceramic-type calcium sulfite beads and said copper-zinc filter media are placed in said shower filter container in approximately equal volumetric portions.
 11. The method of claim 9 wherein said ceramic binder is a polyacrylic ceramic binder.
 12. The method of claim 11 wherein said ceramic-type calcium sulfite beads and said copper-zinc filter media are placed in said shower filter container in approximately equal volumetric portions.
 13. The method of claim 9 wherein said ceramic binder is a ceramic binder selected from the group consisting of polyvinyl alcohol, polyethylene glycol and polyacrylics.
 14. The method of claim 13 wherein said ceramic-type calcium sulfite beads and said copper-zinc filter media are placed in said shower filter container in approximately equal volumetric portions.
 15. The method of claim 14 wherein said ceramic binder is a polyacrylic ceramic binder.
 16. A method of filtering hot shower water comprising the steps of:combining powdered calcium sulfite with a ceramic binder to form non-soluble ceramic-type beads having a hard, porous exterior shell; placing said non-soluble ceramic-type beads in a shower filter housing as a first bed in said shower filter housing; placing a copper-zinc filter media as a second bed in said shower filter housing; and passing hot shower water through the first bed and the second bed in said shower filter housing to filter the hot shower water.
 17. The method of claim 16 wherein said ceramic binder is selected from the group consisting of polyvinyl alcohol, polyethylene glycol and polyacrylics.
 18. The method of claim 17 wherein said non-soluble ceramic-type calcium sulfite beads and said copper-zinc filter media are placed in said shower filter housing in approximately equal volumetric portions.
 19. The method of claim 16 wherein said ceramic binder is a polyacrylic, and said non-soluble ceramic-type calcium sulfite beads and said copper-zinc filter media are placed in said shower filter housing in approximately equal volumetric portions.
 20. The method of claim 16 wherein said ceramic-type calcium sulfite beads are approximately 50% of the volume of total filtering media in said shower filter housing. 